When SimDock opens, regardless of settings, there is an area at the bottom of the screen into which maximized windows are not allowed to expand into. This happens even when SimDock is moved to other parts of the screen. The area is the size of the SimDock area.
To remedy this, I would suggest a couple solutions (I'm not sure whether these require 3D acceleration):
1. Be able to autohide SimDock into an area where you can hover your mouse over to recover the dock.
2. Make it so SimDock doesn't require an area which windows can't maximize into. This would probably require SimDock to be able to "pop" on top.